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Nikolaus Schaller" , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Tomi Valkeinen , Andreas Kemnade References: <20260528-vm-upstr-v1-1-fb93ef8cbe47@kernel.org> Content-Language: en-GB From: Ivaylo Dimitrov In-Reply-To: <20260528-vm-upstr-v1-1-fb93ef8cbe47@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Applied against 6.18.31, no dice :) [ 11.617523] [drm] Initialized pvr 1.17.4948957 for 56000000.gpu on minor 0 [ 11.674652] omapdss_dss 58000000.dss: bound 58001000.dispc (ops dispc_component_ops [omapdrm]) [ 11.775085] omapdss_dss 58000000.dss: bound 58001000.dispc (ops dsi_vc_flush_receive_data [omapdrm]) [ 12.222930] omapdss_dss 58000000.dss: bound 58001000.dispc (ops dsi_vc_flush_receive_data [omapdrm]) [ 12.245117] omapdss_dss 58000000.dss: bound 58001000.dispc (ops dsi_vc_flush_receive_data [omapdrm]) [ 12.247375] omapdss_dss 58000000.dss: bound 58004000.encoder (ops dsi_vc_flush_receive_data [omapdrm]) [ 12.249267] omapdss_dss 58000000.dss: bound 58006000.encoder (ops dsi_vc_flush_receive_data [omapdrm]) [ 12.284729] [drm] Initialized omapdrm 1.0.0 for omapdrm.0 on minor 1 [ 12.311981] [drm] Enabling DMM ywrap scrolling [ 12.770385] omapdrm omapdrm.0: atomic complete timeout (pipe 0)! [ 22.901306] omapdrm omapdrm.0: [drm] *ERROR* flip_done timed out [ 22.901306] omapdrm omapdrm.0: [drm] *ERROR* [CRTC:67:crtc-0] commit wait timed out [ 33.131256] omapdrm omapdrm.0: [drm] *ERROR* flip_done timed out [ 33.131378] omapdrm omapdrm.0: [drm] *ERROR* [CONNECTOR:66:DSI-1] commit wait timed out [ 43.371307] omapdrm omapdrm.0: [drm] *ERROR* flip_done timed out [ 43.371398] omapdrm omapdrm.0: [drm] *ERROR* [PLANE:34:plane-0] commit wait timed out [ 43.631408] omapdrm omapdrm.0: atomic complete timeout (pipe 0)! [ 43.692504] omapdrm omapdrm.0: [drm] fb0: omapdrmdrmfb frame buffer device [ 54.251342] omapdrm omapdrm.0: [drm] *ERROR* flip_done timed out [ 54.251464] omapdrm omapdrm.0: [drm] *ERROR* [CRTC:67:crtc-0] commit wait timed out [ 64.491302] omapdrm omapdrm.0: [drm] *ERROR* flip_done timed out [ 64.491424] omapdrm omapdrm.0: [drm] *ERROR* [CONNECTOR:66:DSI-1] commit wait timed out [ 74.731323] omapdrm omapdrm.0: [drm] *ERROR* flip_done timed out [ 74.731445] omapdrm omapdrm.0: [drm] *ERROR* [PLANE:34:plane-0] commit wait timed out [ 74.991363] omapdrm omapdrm.0: atomic complete timeout (pipe 0)! [ 85.621307] omapdrm omapdrm.0: [drm] *ERROR* flip_done timed out [ 85.621398] omapdrm omapdrm.0: [drm] *ERROR* [CRTC:67:crtc-0] commit wait timed out [ 95.851287] omapdrm omapdrm.0: [drm] *ERROR* flip_done timed out [ 95.851379] omapdrm omapdrm.0: [drm] *ERROR* [CONNECTOR:66:DSI-1] commit wait timed out [ 106.101257] omapdrm omapdrm.0: [drm] *ERROR* flip_done timed out [ 106.101440] omapdrm omapdrm.0: [drm] *ERROR* [PLANE:34:plane-0] commit wait timed out [ 106.371459] omapdrm omapdrm.0: atomic complete timeout (pipe 0)! [ 106.961334] omapdrm omapdrm.0: atomic complete timeout (pipe 0)! [ 141.301269] omapdrm omapdrm.0: [drm] *ERROR* flip_done timed out [ 141.301269] omapdrm omapdrm.0: [drm] *ERROR* [CRTC:67:crtc-0] commit wait timed out [ 151.531280] omapdrm omapdrm.0: [drm] *ERROR* flip_done timed out [ 151.531402] omapdrm omapdrm.0: [drm] *ERROR* [CONNECTOR:66:DSI-1] commit wait timed out On 28.05.26 г. 13:16 ч., akemnade@kernel.org wrote: > From: Andreas Kemnade > > Some chips need configuration commands to be sent first, before they can > send data. TC358762 for example needs PPI_LPTXTIMECNT configured > and PPI_STARTPPI set to 1 to be able to transmit anything. To be able to > configure such chips, do not send bta sync during writes if no acks are > requested. Instead just wait for the packet to be sent to avoid FIFO > overflows. There might be more to do about acks, but there seem to be > virtually no users of that flag. > > This came to light when fiddling with the Epson Moverio BT-200 display > which consists of 2 TC358762 bridges with SPI funneled through > to the unknown display chip. With that patch the bridge can be accessed, > Reading back registers works, when the above-mentioned registers are set. > > Video mode panel at OMAP4 (BT-200) and video mode at OMAP5 was tested. > > Fixes: e70965386353e ("drm/omap: dsi: simplify write function") > Signed-off-by: Andreas Kemnade > --- > This was not tested on any command mode display, which IMHO should be > done. So droid4 folks: please give it a try > --- > drivers/gpu/drm/omapdrm/dss/dsi.c | 32 +++++++++++++++++++++++--------- > 1 file changed, 23 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c > index 27fe7bca9e2cf..98362b0157023 100644 > --- a/drivers/gpu/drm/omapdrm/dss/dsi.c > +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c > @@ -2194,6 +2194,7 @@ static int dsi_vc_send_null(struct dsi_data *dsi, int vc, int channel) > static int dsi_vc_write_common(struct omap_dss_device *dssdev, int vc, > const struct mipi_dsi_msg *msg) > { > + DECLARE_COMPLETION_ONSTACK(completion); > struct dsi_data *dsi = to_dsi_data(dssdev); > int r; > > @@ -2205,17 +2206,30 @@ static int dsi_vc_write_common(struct omap_dss_device *dssdev, int vc, > if (r < 0) > return r; > > - /* > - * TODO: we do not always have to do the BTA sync, for example > - * we can improve performance by setting the update window > - * information without sending BTA sync between the commands. > - * In that case we can return early. > - */ > + /* wait for IRQ for long packet transmission confirmation */ > + r = dsi_register_isr_vc(dsi, vc, dsi_completion_handler, > + &completion, DSI_VC_IRQ_PACKET_SENT); > + if (r) > + return r; > > - r = dsi_vc_send_bta_sync(dssdev, vc); > - if (r) { > - DSSERR("bta sync failed\n"); > + if (wait_for_completion_timeout(&completion, > + msecs_to_jiffies(500)) == 0) > + r = -EIO; > + > + dsi_unregister_isr_vc(dsi, vc, dsi_completion_handler, > + &completion, DSI_VC_IRQ_PACKET_SENT); > + > + if (r) > return r; > + > + /* TODO: find out if more needs to be done for MIPI_DIS_MSG_REQ_ACK */ > + > + if (msg->flags & MIPI_DSI_MSG_REQ_ACK) { > + r = dsi_vc_send_bta_sync(dssdev, vc); > + if (r) { > + DSSERR("bta sync failed\n"); > + return r; > + } > } > > /* RX_FIFO_NOT_EMPTY */ > > --- > base-commit: e7ae89a0c97ce2b68b0983cd01eda67cf373517d > change-id: 20260528-vm-upstr-c8e7634ebf56 > > Best regards, > -- > Andreas Kemnade > >